'Contagious' peeing may have deep evolutionary roots, chimp study

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Infectious urination was seen amongst chimps at the Kumamoto Sanctuary in Japan. Scientists believe it might assist enhance social bonds amongst the group.
(Image credit: Kumamoto Sanctuary)

Chimpanzees tend to pee when others in their group do, in a phenomenon researchers have actually called “contagious urination.”

Since groups of individuals typically go to the restroom together too, and chimpanzees are our’closest living family members, this social habits might be traced back to our typical forefather, scientists stated.

“In humans, we know that our decision to urinate is influenced by social contexts that lead us to urinate simultaneously with others, and that this simultaneous urination could also promote further social bonding,” research study co-author Shinya Yamamotoa wildlife scientist at Kyoto University, informed Live Science in an e-mail. “Our study with chimpanzees clearly shows that they share some similarities in this phenomenon, suggesting the deep evolutionary origin of contagious urination.”

The group chose to study the habits after seeing that a group of chimpanzees at a zoo tended to urinate at about the exact same time, and questioned whether it might be comparable to infectious yawning, which has actually been observed in other primates and wolves

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For the research study, released Monday (Jan. 20) in the journal Present Biologyscientists observed 20 chimpanzees in captivity at the Kumamoto Sanctuary in Japan for more than 600 hours.

They discovered that when one chimpanzee in the group peed, others were most likely to follow. The scientists taped the variety of urinations that took place within 60 seconds of one another, and after that compared these information with randomized computer system simulations. The research study discovered that this infectious urination habits increased with physical distance, so chimpanzees seeing another chimpanzee near to them peeing were most likely to do the same.

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The researchers discovered social ranking affected infectious peeing, with lower ranking members most likely to pee when others did. (Image credit: Kumamoto Sanctuary)

Social rank likewise affected this habits: Chimpanzees with lower supremacy ranks were most likely to pee when others were peeing. Social nearness, determined by time in close distance and grooming with another chimpanzee, had no result on the peeing phenomenon– unlike with social yawning, which increases in socially more detailed sets

Infectious urination might be essential to social group cohesion, coordination or enhancing social bonds, the scientists stated.

The habits might exist to motivate “state-matching,” where chimpanzees enhance group cohesion by all remaining in a comparable state, research study co-author Ena Onishia wildlife scientist at Kyoto University, informed Live Science in an e-mail. The habits might likewise enhance social connections.

Another possibility is that numerous chimpanzees urinating in a single place can discourage or puzzle predators, by minimizing the threat of being tracked through spread urine smells.

While no comparable research studies have actually yet been carried out on chimpanzees in the wild, some scientists have actually kept in mind comparable habits in wild populations, Onishi stated. The scientists are likewise curious about whether other types reveal this infectious urination habits.

“We are greatly influenced by the presence of others, even in mundane activities,” Onishi stated. “For example, in both chimpanzees and humans, behaviors like yawning, walking, rhythmic tapping, and even pupil size are known to be contagious.”

Studying infectious urination might assist researchers comprehend the habits of human beings’ typical forefathers with chimpanzees, and the origin of the social customized in human beings, Onishi stated.”

Olivia Ferrari is a New York City-based freelance reporter with a background in research study and science interaction. Olivia has actually lived and operated in the U.K., Costa Rica, Panama and Colombia. Her composing concentrates on wildlife, ecological justice, environment modification, and social science.